The present invention relates generally to a heat dissipation device for removing heat from a heat generating device, such as an electronic device that generates heat during operation thereof, and in particular to a heat dissipation device comprised of a multiple heat sink structure for efficiently removing heat from the heat generating device and effectively maintaining normal operation temperature of the device.
A lot of electronic devices, such as central processing units, generate heat when they are in operation. Such heat must be timely removed otherwise the electronic device malfunctions due to improper high temperature caused by the heat. A variety of heat dissipation devices are available in different forms, among which a heat sink that comprises a base for positioning on and in physical engagement with the electronic device and a number of spaced fins extending from the base is one of most common ones.
With the trend of minimization, the overall size of electronic devices is increasingly reduced. The heat sink that is positioned on the electronic device for physical engagement with the electronic device substantially increases the height of the electronic device. Thus, heat sinks that are positioned remotely from the electronic device and that are thermally coupled to the electronic device by heat pipes are known. In this case, the heat sink is positioned at substantially the same plane of the electronic device, no longer being stacked on the electronic device. This saves the space above the electronic device required for the stacking type heat sink.
On the other hand, once the amount of heat removed per unit time by the heat sink reaches the limit of the capacity of the heat sink, the temperature of the electronic device still rises, eventually causing malfunction of the electronic device. It is known to add an extra heat sink in cascade to the original heat sink for enhanced heat removal rate. This is not efficient in effectively reducing temperature of the electronic device.
Thus, an object of the present invention is to provide a heat dissipation device comprised of a multiple heat sink structure for enhancing heat removal rate.
Another object of the present invention is to provide a heat dissipation device comprised of two and more heat sinks thermally coupled to an electronic device in a parallel manner for efficiently removing heat from the electronic device.
A further object of the present invention is to provide a heat dissipation device comprised of a multiple heat sink structure which includes a forced convection fan system for inducing forced convection to further enhance heat removal rate.
To achieve the above objects, in accordance with the present invention, there is provided a heat dissipation device comprised of a multiple beat sink structure comprising a contact pad positionable on a heat generating device, such as a central processing unit, and at least two heat sinks arranged on opposite sides of the contact pad and each directly and thermally coupled to the contact pad by heat pipes. Many heat-radiating fins are attached or formed on each heat sink. Fans are coupled to the heat sinks by air passages for providing air stream to induce forced convection.